Grading device



Nov. 21, 1944. s. c. MAURICE GRADING DEVICE Filed June 18, 1942 d IHJAJ/la/Adal iff! nl Il! Jr il @TQ oooeooeooeooo@ Patented Nov. 21, 1944 Para GnAnmG DEv 1on vSturge cgMaui-ice, Kittannini'la. s A' I npplicaunnJuneis, 1942, sentiva-447,489

2c1snns. (c1. 209-315) l y u Thisf invention relates .to means for grading material such as coal and has for an object Vto p roduce a coal grading'device which is eiective I -in operation .and which is ofsimple structure. A furtherobject of this invention is to produce a. grading device of the typeindicated which will eectivelyand efficiently separate material such as run of mine coal into at least four grades such, for exampleasegg coal, nut coa1,`p e a'coal and slack coal. i

`Materialgra 'ng devices are well known and it is-oldpractice to employ ya series of vertically arrangedfscreens of different mesh for the. purpose of accomplishinga desired gradingof materials such as grain, ,oreL and coal. M y invention, however, relates particularly to specific structural features which contributeto simplicity-of structure and eiectivenessin operation of such devices., i A l 'i In the-drawing accompanying and forming a part hereofFigure 1 is a diagrammatic sectional View of a coal grading device embodying my in vention, a'fportion of they device being vbroken away forconvenience of illustration. Figure 2 is .a somewhat diagrammatic view of aspring bumper'shown in association with astop, forming-apart of the structure illustrated in Figure 1 Figure 3 is a fragmental View on a reduced scale and illustratesv a driving mechanism which may be employed for the grading device.

As illustrated,1the grading device includes a trough-shaped frame 3which is so mounted that it is capable of being reciprocated in a horizontal direction, i. e., moved back and forth ,along its supporting base. While the mounting means employed forms no part of my invention, I have diagrammatically illustrated the trough-shaped member 3 asmounted onvrails 4 by means of rollers or anged wheels 5a, which facilitate the reciprocatory motion and whichare so varranged as to guide the frame during its reciprocations.

vAs illustrated, the frame 3supports'a grading screen 5 which is shown divided into relative- Screen sections "I are mounted in -a frame la which is suspended` below thescreensectons. Frame la is ,diagrammatically shown formed of angle irons and'issufciently rigidto prevent the screen sections I-from distortingunder the varyingv load'conditions encountered. One of Athe features of the ,present invention is that the screen 'frame 'Ia is suspendedfrom the side walls ofthe trough-shaped section and is capable of swinging relatively theretothrough a short arc. The extent orY amplitude rof theswing is limited at one end by a buier 8 andat the other end by a spring bumper 9'. As'illustrated, the screen sections 'I and theirfsupporting frame la are suspended by means of links lil, one end of each of which is pivotally securedtoone side of the trough-shaped member 3 whilethe other end is pivotally secured to one side" of the screen frame ,'Ia. `It willV be understood that -each side of the screen framela is supported by links I0 and that thescreen frame is of'such width, with relation to `the width of the trough-shaped structure 3,

` as to provide for the yfree swing of the frame but yly short sections located in stepped relationship Vrelatively to each other.V Thescreensections 5 1155 .eachsuch stop will 4cooperate with a separate It will be understood at the vsame time' prevent the passage of coal lof appreciable size between the sides of the screen frame and the sides/'o the trough-shaped structure. l

The screen frame is .so suspended that it is inclined downwardlyin the direction of coal movement across it. 5 In addition, eachv suspending link Il) is so positionedwith relation to its supporting trunnion I I and its frame-connecting pin I2 that Vthe frame is 'normally held by its own weight against the buffer or buffers 8. In the i1- ylustrated embodiment the buier or buffers 8 are -formed Aof rubber or some .suchv resilient material and are supported on angle irons which constitute cross struts of the structure 3. yEach mounted on a sidewall of the structure 3. A i I As shown, each bumper is provided with an extension I3 which projects into a'pipe section or cylinder I4 and butts against a coil'spring I5 lo'- v cated within the cylinder. As shown, the cylinder Mis carried by an angular bracket I6 which .is adapted :to bemounted on one ofthe sidewalls of the trough-shaped structure3. As illustrated in Figure 2,the screenframe lamaybe provided with an upwardly projecting block or stop I1 vwhichisadapted toengage the bumper 9 and thus Vlimit the swing of the screen in onedirection.i It will be understood that. the screen `frame will preferably be provided with two'such -stopsfflocated on opposite sides thereof, and that bumper 3 and thus avoid placing a side or twisting strain on the screen and screen frame each time its movement is stopped as it swings in the direction of coal movement across it. The angle bracket I6 is provided with a plurality of boltreceiving apertures Isa to accommodate mountlng the bumper in the desired or anadjusted position with relation to its cooperating stop l1. It

vwill be understood that each such bracket is bolted toa side wall of the structure 3 by means of bolts which pass through some ol?V the apertures 16a and suitably located bolt-receiving apertures in such side walls.

In the illustrated embodiment, screens 1 are intended to pass all coal of less size than nut coal and are so positioned with relation-tov a floor t3.

that the nut coal moving across them is delivy ered onto the floor I8 and moved'across that ilor in response to the reciprocations of the troughshaped structure 3. As shown, rfloor I8 is downwardly inclinedv in thed'iiection of' coal"m'ovecontribute to the deliveryof the' coal along the floor, I provide the lower endof'the screen frame asada/is clined in the direction of coal movement along.

it and may be formed in steps, as illustrated, for the purpose of facilitating the movement of the coal along it. It will be understood that the .coal traversing each of the oors 6, I8, 23 and 24 is delivered, by separate conveying means, to

' a separate' bin orreceptacle, as is usual in connection with grading devices. Such conveying mechanisms or chutes form no part of the present invention-and consequently are not illustrated.

In' order to render" the device illustrated highlyeffective as' agrading device,` I preferv tao-employ a reciprocatingmechanismy forthe structure 3v which moves it more rapidly in the direction-of the arrow-26` ofllgurel than in'theopposite (iiwith a plate, I9 which is higdthereto with its free edge' riding ori'the ioor i8.' TheVA plate 'is substantially the width' of the floorY f8 and' provides a way acrosswhich` coal movesirom the frame 1a onto" the floor; v Screen sections 20 are carried b'yja` frame 2l which is suspended from the sidewalls 'of the `Vstructure" 3 and is located below thescreen frame la,v The screen frame' 2T'i`s sof i'cirmedy andthe screen sectionsV are so constructed; as to' prevent the frame and'thescreens from sagging or bendiing under varyingload conditions. Tl'ie'sections 20 are of smaller me'shthantlie' screen sections Tand, in the illustrated' embodiment, are adaptedvl to pass all coal smaller than pea coal;

As shown, the screen made up of the sections 1" is longer (inthe direction of coal" travel across it) than the screen made upof sections 5". Likewise, the screen made up lof' the secticns'l` is longer than the screen sectionof' the frame 1a. TheV screen frame 2l is inclined'downwardly` in the direction of coalu movement; isL suspended by meansv of t0" from the side walls off the structure 3 and the links areso arrsamged as to normally hold the'upper end-of the-'frameagainst a buffer or buffers 22 carried bythe'structure 3.

The swingingymovement of the screen frame2l is limited in one'directionby the buffer or buiiersv 22 as described in connection with screen frame 1a, andv its movement in theV opposite direction is limited by one orv two bumpers 9. The relationship between the screen frame Y2| and its movement-limiting bumpers sf isf the samel as that described in connection withA screen frame la, `and the screen frame 2l lsftherefore' providedl with a block or blocksl |11 for engaging the bumper or bumpersy 8' which; as' previously described in connection with the screen frame Ta, are also carried by the side wal-l of the structure 3; I

As shown, animperf'orate-plate 2-3 is carried by the frame M` and therefore swingsY with the screens 20. As a result, the nut-` coal, moving off `of the screens 20',`contl-nues to move rection, and I- have diagramrriaticallylillustrated a mechanism 'forr accomplishing suchV a` movement. As there shown, the driving means includes a link Z-ROperativel-yr cou-pledto the structures by meansM of alpivot' pin 29?;y The link` is actuated byv means of al lever 3W which is fulcrumed atY 3Iland-.whichisslotted midway of its length to receive aL block 33; The bloc-k*k is pivoted` on a pin 34 whichis carried by a gear' 351. The gear ismounted' for rotation` any suitable andA rigidlyv supported bearing and is-drivefn in a counter-clockwise direction by means of' a pinion 36 With this-arrangement the structure 3" is moved more rapidly in' thel direction opposite tothat of coaltravel alo-ng the screcns'thanin-the direction of coal-travel, with the result that the cooperative action or the bumper-sA 8f' andthe driving mechanismsoYIi-nifluericesthe'L swing of each of the screen frames 'Paf and 2l waste accomplish an effec-tive shiftingof the coal onthe screens and at the samey time a propellingof the coal in the-desired direction of travel;

As shown, the pin! and the block. 3.3 are adjustable radially of the gears 352 byr means of a screwV 31. is ordinaryfand usual construction andf therefore is notl fully illustrated?. It,

lhowever, will be apparent that by shifting the block 33l toward and away from-the center of rotation of the gear 35', the amplitude of: thea reciprocatons of the structure 3- will' be varied. This in turn will cause sornechange in the movement of the coal on the various'screens and will thus have some effect-on the/grading operations.

While I have described butone embodiment. of myf invention, it will be apparent thatV various changes in the structural details.A and additions and omissions` may be made? the apparatus illustrated' Without departingtrom the spirit` and scope of Vmy inventiona's dencdbytheappended claims. v

What I- claim is:

shaped structure mounted for i reciprocatory` movement, a conveyor licor' inclined: tothe hori- 'z'ontalg extending substantial-'ly in the4 direction of movement oi saidf structure and' xedlv' secured thereto above the bottomv thereof and including atleast one grading screen intermediate its ends,

, a swinging screen located within said structure,

suspended from.- the walls thereof below said firstmentioned screen, and inclined to the horizontal, stops for limiting the swing o-f said swinging screen located at opposite ends thereof, one such screens located in stepped relationship and con-r stituting an'r intermediate part of said floor, a second conveyor floor located below said Irstmentioned oor extending substantially parallel thereto and flxedly secured to said structure, a swinging'screen located within said structure below said first-mentioned screens and overlapping said second floor, links pivotally secured to said structure and to said swinging screen and supporting said screen in an inclined position, a separate stop located at each end of said swinging screen and carried by said structure for limiting the amplitude of the swing of said swinging screen, the stop located at the upper end of said screen lbeing so positioned that the swinging screen is normally held against it by gravity, and

means for reciprocatingr said structure and moving' it more rapidly inthe direction of travel of material to be graded over said floors than in the opposite direction. i

STURGE C. MAURICE. 

